ualarm - schedule signal after interval in microseconds
useconds_t ualarm(useconds_t useconds, useconds_t interval);
The ualarm() function causes the SIGALRM signal to be gen-
erated for the calling process after the number of real-time
microseconds specified by the useconds argument has elapsed.
When the interval argument is non-zero, repeated timeout
notification occurs with a period in microseconds specified
by the interval argument. If the notification signal,
SIGALRM, is not caught or ignored, the calling process is
Because of scheduling delays, resumption of execution when
the signal is caught may be delayed an arbitrary amount of
Interactions between ualarm() and either alarm(2) or
sleep(3C) are unspecified.
The ualarm() function returns the number of microseconds
remaining from the previous ualarm() call. If no timeouts
are pending or if ualarm() has not previously been called,
ualarm() returns 0.
No errors are defined.
The ualarm() function is a simplified interface to setiti-
mer(2), and uses the ITIMER_REAL interval timer.
alarm(2), setitimer(2), sighold(3C), signal(3C), sleep(3C),
Man(1) output converted with